Monday, December 22, 2008

why cells are small

Sorry I could not find the table I was talking about last time. However, I found the following notes (which can be converted to a table, but I don't have time, sorry) in my notebook: In a cell, equilibrium through diffusion is attained within 0.00000456 seconds if the distance from the boundary is 0.1 of a micrometer. If the distance is 1 micrometer, then equilibrium is attained within 0.000456 seconds and if the distance is 10 micrometer, then equilibrium is attained within 0.0456 seconds. If however the distance from the boundary is 1 mm, then equilibrium is attained only after 7.6 minutes while if it is 1 cm, then it would take 12.75 hours for equilibrium to be attained.

If we examine the figures above therefore, it is obvious why cells have to be small, that is, they are in micrometers. A red blood cell for example is about 7 micrometers. Just imagine what will happen if a cell is in centimeters, it would take several hours (half a day, actually!) for substances to move from the cell membrane to the cytoplasm. That is not compatible with life at all! And if the cell is as big as a basketball, can you imagine how long equilibrium by diffusion would take? - months maybe or would it be years? Oh no!

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Welcome

Hi,Welcome to my cell blog. The reason for this blog is written in my first post "why this blog" last October. Writing/talking about cells has developed into a kind of mission for me. I hope you will join me daily or visit every now and then and discover or rediscover more about the wonders of the cell.

This blog is dedicated to my former students and teachers who inspired me through the years. It is especially dedicated to the high school teachers who requested me to write a book. This might serve as a prelude to a book, who knows.

Please leave comments if anything strikes you or you may write me at my email - baby.angtuaco@gmail.comIf you have questions or if you want me to write anything about cells please tell me too. We can work on this together.

I got several blogs one of which is: http://getinspired-photoquotes.blogspot.com/ wherein I share inspirational quotes with photos. I also have other blogs on photography, happiness, and science, as well as about the Philippines.